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the dense mallee scrub between Ardrossan, Yorke Valley, and 

 Kalkabury upon gently inclined flats, and their immediate 

 neighbourhood is at once made manifest by a distinct vegeta- 

 tion, including Eucalyptus incrassata, Callestemon coccineus, 

 Juncus pallidus, and J. hufonms, &c, which depend on the 

 greater moisture there obtainable. In a similar manner even 

 lakelets of some extent may be formed anew by the closing 

 or chocking up of the subterranean vents for draining off the 

 rainwater. Thus since about 1852, an almost permanent sheet of 

 water has covered an area of some 120 acres at Hoffnungsthal, 

 near Lyndoch, which had been farmed for several years and 

 produced some splendid crops of wheat. The soil consisted of 

 deep black loam — friable Avhen dry, stiff and adhesive when 

 wet. Under this a } r ellow arenaceous clay followed, becoming- 

 more and more gravelly at increased depths, till at sixteen to 

 twenty feet brackish water stopped further sinking. This 

 basin, inclosed on three sides by high hills of micaceous slates, 

 hornblende schists, quartzites, &c, and at the fourth by a 

 small rising plain, through which at a distance of about a mile 

 a brook flowed, whose bed was at a higher level than that of the 

 basin, had been overgrown with grass and numerous eucalypts, 

 and never observed to contain stagnant water while in its 

 natural state. The drainage received from a considerable area 

 for the locality no doubt then escaped by numerous under- 

 ground channels, which were choked when the farmers' plough 

 broke the turf and produced more sediment than could be 

 carried along. The first inundation lasted some three months 

 only, when the ground became sufficiently dry for another 

 crop, which grew most luxuriantly, till in the succeeding 

 August it was overwhelmed again by the water in augmented 

 quantity. But only the third year beheld its permanency, the 

 water henceforth being only removed by evaporation. This 

 fact, together with the death of the trees after the first flood, 

 proves the gradual closing of the underground outlets (caused 

 by the stirring of the soil), and thereby the correctness of the 

 theory. Some people believed that the opening of the subter- 

 ranean springs (according to the popular but fallacious idea 

 that tillage, &c, facilitates their increase) was the cause, but 

 this would demand complicated phenomena, the occurrence of 

 which to assume is not warranted in the slightest degree by 

 the surrounding country. It is to be mentioned that out of 

 six or seven wells sunk around the margin only two contained 

 fresh water, the rest so brackish as scarcely to be fit for cattle. 

 The flood water was at first quite fresh, but in the course of 

 years assumed a more and more saline character, and now the 

 whole has the general aspect of an ordinary salt lagoon. The 

 above naturally suggests that this and similar other areas in 



